Recently, an ingredient in my moisturizer caught my attention: squalene. I hadn’t heard much about it and I wanted to know exactly what it is and what it does.
Traditional medicines have used squalene or squalane (saturated form) for ages. It is an essential building block for the synthesis of hormones, cholesterol, and other substances (Food and Drug Administration).
This naturally occurring compound is found in a large abundance in shark liver and makes up for 13% of human sebum (Advances in Food and Nutrition Research). In fact, shark liver oil, with its large amount of squalene, is sold as a dietary supplement in the United States (American Cancer Society). But some companies have made a commitment not to use squalene derived from sharks. In 2008, Unilever, Ponds, and Dove announced the removal of shark squalene in their cosmetics (Oceana).
But shark liver isn’t the only substance with squalene. Olive oil, wheat germ oil, rice bran oil, and among many foods produce squalene (National Academy of Sciences). This ingredient has been extensively studied and is found in food, cosmetics, over the counter medication and health supplements.
Protection Against Aging and Free Radicals
Squalene is an isoprenoid hydrocarbon that provides beneficial antioxidants that may protect against aging. Particularly this time of year, when people spend more time outdoors, the sun can do a number on your skin (and cells!).
UV exposure is related to skin aging and cancer by singlet oxygen (Biophysical Journal). Peroxidation is a process which results in cell damage and production of free radicals. Squalene is not susceptible to peroxidation, it protects the skin from lipid peroxidation from sources of radiation like UV and acts as a singlet quencher (Alternative Medicine Review).
An experiment studing the quenching reaction of singlet oxygen and scavenging reaction of free radicals by squalene concluded squalene provides natural skin protection against high exposure to the sun (Biochimica et Biophysical Acta (BBA)-Lipids and Lipid Metabolism).
Natural Skin Protection and Hydration
We produce this compound in our skin, hair, and other surface lipids, so it is a natural process for skin protection and hydration (Free Radical Research). Moisturizers containing squalene keep skin soft, smooth, and moist. Because our bodies recognize squalene as a compound produced by our bodies naturally, it quickly absorbs into the skin and does not leave an oily residue (Science Based Medicine).
Squalene also helps heal skin barrier for protection. Vernix caseosa (VC) is a cream used to treat barrier deficient skin. In newborns and fetuses, it acts as a lubricant, an anti-infective, antioxidant, and provides hydration. A study comparing isolated lanolin along with squalene, triglycerides, cholesterol, and fatty acids concluded that the new synthetic mixture produced a similar effect to vernix caseosa  (Biochimica et Biophysica Acta (BBA) – Biomembranes).
Antifungal Properties
Along with protecting against aging, skin cancer and moisturizing abilities, squalene also exhibits anti-fungal properties. Candidiasis is a fungal infection caused by yeast normally found on skin and mucous membranes (Centers for Disease Control and Prevention). Experiments have shown that squalene enhances Amphotericin-B (antifungal drug) and fights against a number of candida species (The Journal of Antibiotics).
Bottom line
Squalene is a beneficial ingredient if you are on the lookout for a new moisturizer. It has anti aging, anti-skin-cancer, and fungal properties. Since this compound is found in the sebum of our skin, it is easily absorbed and is effective in hydration. As for many products, it may cause irritation with redness so remember to test in a small area of the skin before use (Environmental Health and Safety).